行為變更：指定 Android 15 以上版本的應用程式

和先前版本一樣，Android 15 也包含可能會影響應用程式的行為變更。以下行為變更僅適用於指定 Android 15 以上版本的應用程式。如果您的應用程式指定 Android 15 以上版本，建議您視情況修改應用程式，以便支援這些行為。

此外，無論應用程式的 targetSdkVersion 為何，請務必查看影響所有在 Android 15 上執行的應用程式行為變更清單。

核心功能

Android 15 會修改或擴充 Android 系統的各種核心功能。

前景服務變更

We are making the following changes to foreground services with Android 15.

• Data sync foreground service timeout behavior
• New media processing foreground service type
• Restrictions on BOOT_COMPLETED broadcast receivers launching foreground services
• Restrictions on starting foreground services while an app holds the SYSTEM_ALERT_WINDOW permission

Data sync foreground service timeout behavior

Android 15 為指定 Android 15 (API 級別 35) 以上版本為目標版本的應用程式，在 dataSync 中導入新的逾時行為。這項行為也適用於新的mediaProcessing前景服務類型。

系統允許應用程式的 dataSync 服務在 24 小時內執行總共 6 小時，之後系統會呼叫執行中的服務 Service.onTimeout(int, int) 方法 (在 Android 15 中推出)。此時，服務有幾秒的時間可以呼叫 Service.stopSelf()。呼叫 Service.onTimeout() 後，系統就不會再將服務視為前景服務。如果服務未呼叫 Service.stopSelf()，系統會擲回內部例外狀況。例外狀況會記錄在 Logcat 中，並顯示以下訊息：

Fatal Exception: android.app.RemoteServiceException: "A foreground service of
type dataSync did not stop within its timeout: [component name]"

如要避免這項行為變更帶來的問題，您可以執行下列一或多項操作：

1. 讓您的服務實作新的 Service.onTimeout(int, int) 方法。應用程式收到回呼時，請務必在幾秒內呼叫 stopSelf()。(如果您沒有立即停止應用程式，系統會產生失敗)。
2. 確認應用程式的 dataSync 服務在任何 24 小時內的執行時間不超過 6 小時 (除非使用者與應用程式互動，並重設計時器)。
3. 只有在使用者直接互動時，才啟動 dataSync 前景服務；由於服務啟動時應用程式處於前景，因此服務在應用程式進入背景後，可執行完整的六小時。
4. 請改用其他 API，而非 dataSync 前景服務。

如果應用程式的 dataSync 前景服務在過去 24 小時內已執行 6 小時，則「除非」使用者將應用程式移至前景 (會重設計時器)，否則您無法啟動另一項 dataSync 前景服務。如果您嘗試啟動另一項 dataSync 前景服務，系統會擲回 ForegroundServiceStartNotAllowedException，並顯示錯誤訊息「Time limit is Of for 前景服務類型 dataSync」

測試

如要測試應用程式的行為，您可以啟用資料同步處理逾時，即使應用程式並非以 Android 15 為目標版本 (只要應用程式是在 Android 15 裝置上執行)，也能啟用。如要啟用逾時值，請執行下列 adb 指令：

adb shell am compat enable FGS_INTRODUCE_TIME_LIMITS your-package-name

您也可以調整逾時期限，方便測試應用程式在達到限制時的行為。如要設定新的逾時期限，請執行下列 adb 指令：

adb shell device_config put activity_manager data_sync_fgs_timeout_duration duration-in-milliseconds

New media processing foreground service type

Android 15 introduces a new foreground service type, mediaProcessing. This service type is appropriate for operations like transcoding media files. For example, a media app might download an audio file and need to convert it to a different format before playing it. You can use a mediaProcessing foreground service to make sure the conversion continues even while the app is in the background.

The system permits an app's mediaProcessing services to run for a total of 6 hours in a 24-hour period, after which the system calls the running service's Service.onTimeout(int, int) method (introduced in Android 15). At this time, the service has a few seconds to call Service.stopSelf(). If the service does not call Service.stopSelf(), the system throws an internal exception. The exception is logged in Logcat with the following message:

Fatal Exception: android.app.RemoteServiceException: "A foreground service of
type mediaProcessing did not stop within its timeout: [component name]"

To avoid having the exception, you can do one of the following:

1. Have your service implement the new Service.onTimeout(int, int) method. When your app receives the callback, make sure to call stopSelf() within a few seconds. (If you don't stop the app right away, the system generates a failure.)
2. Make sure your app's mediaProcessing services don't run for more than a total of 6 hours in any 24-hour period (unless the user interacts with the app, resetting the timer).
3. Only start mediaProcessing foreground services as a result of direct user interaction; since your app is in the foreground when the service starts, your service has the full six hours after the app goes to the background.
4. Instead of using a mediaProcessing foreground service, use an alternative API, like WorkManager.

If your app's mediaProcessing foreground services have run for 6 hours in the last 24, you cannot start another mediaProcessing foreground service unless the user has brought your app to the foreground (which resets the timer). If you try to start another mediaProcessing foreground service, the system throws ForegroundServiceStartNotAllowedException with an error message like "Time limit already exhausted for foreground service type mediaProcessing".

For more information about the mediaProcessing service type, see Changes to foreground service types for Android 15: Media processing.

Testing

To test your app's behavior, you can enable media processing timeouts even if your app is not targeting Android 15 (as long as the app is running on an Android 15 device). To enable timeouts, run the following adb command:

adb shell am compat enable FGS_INTRODUCE_TIME_LIMITS your-package-name

You can also adjust the timeout period, to make it easier to test how your app behaves when the limit is reached. To set a new timeout period, run the following adb command:

adb shell device_config put activity_manager media_processing_fgs_timeout_duration duration-in-milliseconds

Restrictions on BOOT_COMPLETED broadcast receivers launching foreground services

BOOT_COMPLETED 廣播接收器啟動有一些新限制 前景服務BOOT_COMPLETED 接收器無法啟動 下列類型的前景服務：

• dataSync
• camera
• mediaPlayback
• phoneCall
• mediaProjection
• microphone (我們已對 microphone 設下這項限制，自 Android 14)

如果 BOOT_COMPLETED 接收器嘗試啟動任何這些類型的前景 服務就會擲回 ForegroundServiceStartNotAllowedException。

測試

如要測試應用程式的行為，即使應用程式並非以 Android 15 為目標版本 (只要應用程式是在 Android 15 裝置上執行)，您也可以啟用這些新限制。執行下列 adb 指令：

adb shell am compat enable FGS_BOOT_COMPLETED_RESTRICTIONS your-package-name

如要在不重新啟動裝置的情況下傳送「BOOT_COMPLETED」廣播訊息，請按照下列步驟操作： 執行下列 adb 指令：

adb shell am broadcast -a android.intent.action.BOOT_COMPLETED your-package-name

Restrictions on starting foreground services while an app holds the SYSTEM_ALERT_WINDOW permission

先前，如果應用程式擁有 SYSTEM_ALERT_WINDOW 權限，即使目前處於背景執行狀態，也能啟動前景服務 (如「背景啟動限制的例外狀況」一文所述)。

如果應用程式指定 Android 15 為目標版本，這項豁免權現在比較縮小。應用程式現在需要具備 SYSTEM_ALERT_WINDOW 權限，且也設有可見的重疊視窗。也就是說，應用程式必須先啟動 TYPE_APPLICATION_OVERLAY 視窗，「而且」必須先顯示該視窗，才能啟動前景服務。

如果應用程式嘗試從背景啟動前景服務，但不符合這些新要求 (且沒有其他例外狀況)，系統會擲回 ForegroundServiceStartNotAllowedException。

如果您的應用程式聲明 SYSTEM_ALERT_WINDOW 權限，並從背景啟動前景服務，可能會受到這項變更的影響。如果應用程式收到 ForegroundServiceStartNotAllowedException，請檢查應用程式的運算順序，並確認應用程式在嘗試從背景啟動前景服務前，已擁有有效的疊加式視窗。您可以呼叫 View.getWindowVisibility()，檢查覆疊視窗目前是否可見，也可以覆寫 View.onWindowVisibilityChanged()，在可見度變更時收到通知。

測試

如要測試應用程式的行為，您可以啟用這些新限制，即使應用程式並非以 Android 15 為目標版本 (只要應用程式在 Android 15 裝置上執行) 也一樣。如要啟用這些新限制，以便從背景啟動前景服務，請執行下列 adb 指令：

adb shell am compat enable FGS_SAW_RESTRICTIONS your-package-name

變更應用程式修改零打擾模式全域狀態的時機

Apps that target Android 15 (API level 35) and higher can no longer change the global state or policy of Do Not Disturb (DND) on a device (either by modifying user settings, or turning off DND mode). Instead, apps must contribute an AutomaticZenRule, which the system combines into a global policy with the existing most-restrictive-policy-wins scheme. Calls to existing APIs that previously affected global state (setInterruptionFilter, setNotificationPolicy) result in the creation or update of an implicit AutomaticZenRule, which is toggled on and off depending on the call-cycle of those API calls.

Note that this change only affects observable behavior if the app is calling setInterruptionFilter(INTERRUPTION_FILTER_ALL) and expects that call to deactivate an AutomaticZenRule that was previously activated by their owners.

OpenJDK API 異動

Android 15 continues the work of refreshing Android's core libraries to align with the features in the latest OpenJDK LTS releases.

Some of these changes can affect app compatibility for apps targeting Android 15 (API level 35):

• Changes to string formatting APIs: Validation of argument index, flags, width, and precision are now more strict when using the following String.format() and Formatter.format() APIs:

  • String.format(String, Object[])
  • String.format(Locale, String, Object[])
  • Formatter.format(String, Object[])
  • Formatter.format(Locale, String, Object[])

  For example, the following exception is thrown when an argument index of 0 is used (%0 in the format string):

  IllegalFormatArgumentIndexException: Illegal format argument index = 0
  

  In this case, the issue can be fixed by using an argument index of 1 (%1 in the format string).

• Changes to component type of Arrays.asList(...).toArray(): When using Arrays.asList(...).toArray(), the component type of the resulting array is now an Object—not the type of the underlying array's elements. So the following code throws a ClassCastException:

  String[] elements = (String[]) Arrays.asList("one", "two").toArray();
  

  For this case, to preserve String as the component type in the resulting array, you could use Collection.toArray(Object[]) instead:

  String[] elements = Arrays.asList("two", "one").toArray(new String[0]);
  

• Changes to language code handling: When using the Locale API, language codes for Hebrew, Yiddish, and Indonesian are no longer converted to their obsolete forms (Hebrew: iw, Yiddish: ji, and Indonesian: in). When specifying the language code for one of these locales, use the codes from ISO 639-1 instead (Hebrew: he, Yiddish: yi, and Indonesian: id).

• Changes to random int sequences: Following the changes made in https://bugs.openjdk.org/browse/JDK-8301574, the following Random.ints() methods now return a different sequence of numbers than the Random.nextInt() methods do:

  • Random.ints(long)
  • Random.ints(long, int, int)
  • Random.ints(int, int)
  • Random.ints()

  Generally, this change shouldn't result in app-breaking behavior, but your code shouldn't expect the sequence generated from Random.ints() methods to match Random.nextInt().

The new SequencedCollection API can affect your app's compatibility after you update compileSdk in your app's build configuration to use Android 15 (API level 35):

• Collision with MutableList.removeFirst() and MutableList.removeLast() extension functions in kotlin-stdlib

  The List type in Java is mapped to the MutableList type in Kotlin. Because the List.removeFirst() and List.removeLast() APIs have been introduced in Android 15 (API level 35), the Kotlin compiler resolves function calls, for example list.removeFirst(), statically to the new List APIs instead of to the extension functions in kotlin-stdlib.

  If an app is re-compiled with compileSdk set to 35 and minSdk set to 34 or lower, and then the app is run on Android 14 and lower, a runtime error is thrown:

  java.lang.NoSuchMethodError: No virtual method
  removeFirst()Ljava/lang/Object; in class Ljava/util/ArrayList;
  

  The existing NewApi lint option in Android Gradle Plugin can catch these new API usages.

  ./gradlew lint
  
  MainActivity.kt:41: Error: Call requires API level 35 (current min is 34): java.util.List#removeFirst [NewApi]
        list.removeFirst()
  

  To fix the runtime exception and lint errors, the removeFirst() and removeLast() function calls can be replaced with removeAt(0) and removeAt(list.lastIndex) respectively in Kotlin. If you're using Android Studio Ladybug | 2024.1.3 or higher, it also provides a quick fix option for these errors.

  Consider removing @SuppressLint("NewApi") and lintOptions { disable 'NewApi' } if the lint option has been disabled.

• Collision with other methods in Java

  New methods have been added into the existing types, for example, List and Deque. These new methods might not be compatible with the methods with the same name and argument types in other interfaces and classes. In the case of a method signature collision with incompatibility, the javac compiler outputs a build-time error. For example:

  Example error 1:

  javac MyList.java
  
  MyList.java:135: error: removeLast() in MyList cannot implement removeLast() in List
    public void removeLast() {
                ^
    return type void is not compatible with Object
    where E is a type-variable:
      E extends Object declared in interface List
  

  Example error 2:

  javac MyList.java
  
  MyList.java:7: error: types Deque<Object> and List<Object> are incompatible;
  public class MyList implements  List<Object>, Deque<Object> {
    both define reversed(), but with unrelated return types
  1 error
  

  Example error 3:

  javac MyList.java
  
  MyList.java:43: error: types List<E#1> and MyInterface<E#2> are incompatible;
  public static class MyList implements List<Object>, MyInterface<Object> {
    class MyList inherits unrelated defaults for getFirst() from types List and MyInterface
    where E#1,E#2 are type-variables:
      E#1 extends Object declared in interface List
      E#2 extends Object declared in interface MyInterface
  1 error
  

  To fix these build errors, the class implementing these interfaces should override the method with a compatible return type. For example:

  @Override
  public Object getFirst() {
      return List.super.getFirst();
  }
  

安全性

Android 15 包含提升系統安全性的異動，可協助保護應用程式和使用者不受惡意應用程式侵擾。

啟動安全的背景活動

Android 15 可保護使用者不受惡意應用程式侵擾，並讓使用者進一步控管 方法是加入可防止惡意背景應用程式的變更 將其他應用程式移至前景、提升其權限並濫用 互動。自以下日期起，系統已限制啟動背景活動： Android 10 (API 級別 29)。

禁止與堆疊頂端 UID 不符的應用程式啟動活動

惡意應用程式可能會在同一工作中啟動其他應用程式的活動，然後 疊加在上，營造出該應用程式的錯覺這項「工作」 駭客」攻擊會避開目前的背景啟動限制，因為這 發生在相同的可見工作中為降低這種風險，Android 15 新增了 旗標，防止應用程式啟動與堆疊上頂層 UID 不符的應用程式 活動。如要選擇加入應用程式的所有活動，請更新 allowCrossUidActivitySwitchFromBelow敬上 屬性加入應用程式的 AndroidManifest.xml 檔案中：

<application android:allowCrossUidActivitySwitchFromBelow="false" >

如果符合下列所有條件，系統就會啟用新的安全措施：

• 執行啟動作業的應用程式以 Android 15 為目標。
• 工作堆疊頂端的應用程式以 Android 15 為目標。
• 所有可見的活動已選擇採用新的保護措施

啟用安全措施後，應用程式可能會返回主畫面，而非 則最後顯示的應用程式。

其他變更

除了 UID 比對的限制外，下列其他變更也會 包含：

• 變更 PendingIntent 位創作者，禁止開啟背景活動，包括： default。這可避免應用程式意外 PendingIntent，可能遭不肖人士濫用。
• 除非 PendingIntent 傳送者，否則請勿將應用程式移至前景 這項異動旨在避免惡意應用程式濫用 可在背景啟動活動根據預設，應用程式 允許將工作堆疊移至前景，除非創作者允許 背景活動啟動權限或傳送者有背景活動 啟動權限。
• 控管工作堆疊的主要活動如何完成任務。如果 完成一項任務後，Android 就會回到 上次使用時間。此外，如果非頂層活動完成任務，Android 就會 返回主畫面。也不會阻斷 活動。
• 避免從其他應用程式啟動任意活動 工作。這項變更藉由建立 假冒其他應用程式的活動。
• 禁止將不可見的視窗視為背景活動 產品發布。避免惡意應用程式濫用背景 使用者啟動活動後，系統會顯示擾人或惡意的內容。

更安全的意圖

Android 15 推出了新的選用安全措施，讓意圖更安全可靠。這些異動旨在防止意圖遭到惡意應用程式濫用，並避免潛在的安全漏洞。Android 15 針對意圖的安全性進行了兩項主要改善：

• 比對目標意圖篩選器：如果意圖指定特定元件，就必須準確符合目標的意圖篩選器規格。如果您傳送意圖來啟動其他應用程式的活動，目標意圖元件必須與接收活動宣告的意圖篩選器相符。
• 意圖必須包含動作：沒有動作的意圖將不再與任何意圖篩選器相符。也就是說，用於啟動活動或服務的意圖必須有明確的動作定義。

如要檢查應用程式如何回應這些變更，請在應用程式中使用 StrictMode。如要查看 Intent 使用違規的詳細記錄，請新增下列方法：

fun onCreate() {
    StrictMode.setVmPolicy(VmPolicy.Builder()
        .detectUnsafeIntentLaunch()
        .build()
    )
}

public void onCreate() {
    StrictMode.setVmPolicy(new VmPolicy.Builder()
            .detectUnsafeIntentLaunch()
            .build());
}

使用者體驗和系統使用者介面

Android 15 包含一些變更，旨在打造更一致、直覺的使用者體驗。

視窗插邊變更

Android 15 的視窗插邊有兩項變更：根據預設，系統會強制執行無邊框設計，以及設定變更 (例如系統列的預設設定)。

邊緣到邊緣強制執行

Apps are edge-to-edge by default on devices running Android 15 if the app is targeting Android 15 (API level 35).

This is a breaking change that might negatively impact your app's UI. The changes affect the following UI areas:

• Gesture handle navigation bar
  • Transparent by default.
  • Bottom offset is disabled so content draws behind the system navigation bar unless insets are applied.
  • setNavigationBarColor and R.attr#navigationBarColor are deprecated and don't affect gesture navigation.
  • setNavigationBarContrastEnforced and R.attr#navigationBarContrastEnforced continue to have no effect on gesture navigation.
• 3-button navigation
  • Opacity set to 80% by default, with color possibly matching the window background.
  • Bottom offset disabled so content draws behind the system navigation bar unless insets are applied.
  • setNavigationBarColor and R.attr#navigationBarColor are set to match the window background by default. The window background must be a color drawable for this default to apply. This API is deprecated but continues to affect 3-button navigation.
  • setNavigationBarContrastEnforced and R.attr#navigationBarContrastEnforced is true by default, which adds an 80% opaque background across 3-button navigation.
• Status bar
  • Transparent by default.
  • The top offset is disabled so content draws behind the status bar unless insets are applied.
  • setStatusBarColor and R.attr#statusBarColor are deprecated and have no effect on Android 15.
  • setStatusBarContrastEnforced and R.attr#statusBarContrastEnforced are deprecated but still have an effect on Android 15.
• Display cutout
  • layoutInDisplayCutoutMode of non-floating windows must be LAYOUT_IN_DISPLAY_CUTOUT_MODE_ALWAYS. SHORT_EDGES, NEVER, and DEFAULT are interpreted as ALWAYS so that users don't see a black bar caused by the display cutout and appear edge-to-edge.

The following example shows an app before and after targeting Android 15 (API level 35), and before and after applying insets.

What to check if your app is already edge-to-edge

If your app is already edge-to-edge and applies insets, you are mostly unimpacted, except in the following scenarios. However, even if you think you aren't impacted, we recommend you test your app.

• You have a non-floating window, such as an Activity that uses SHORT_EDGES, NEVER or DEFAULT instead of LAYOUT_IN_DISPLAY_CUTOUT_MODE_ALWAYS. If your app crashes on launch, this might be due to your splashscreen. You can either upgrade the core splashscreen dependency to 1.2.0-alpha01 or later or set window.attributes.layoutInDisplayCutoutMode = WindowManager.LayoutInDisplayCutoutMode.always.
• There might be lower-traffic screens with occluded UI. Verify these less-visited screens don't have occluded UI. Lower-traffic screens include:
  • Onboarding or sign-in screens
  • Settings pages

What to check if your app is not already edge-to-edge

If your app is not already edge-to-edge, you are most likely impacted. In addition to the scenarios for apps that are already edge-to-edge, you should consider the following:

• If your app uses Material 3 Components ( androidx.compose.material3) in compose, such as TopAppBar, BottomAppBar, and NavigationBar, these components are likely not impacted because they automatically handle insets.
• If your app is using Material 2 Components ( androidx.compose.material) in Compose, these components don't automatically handle insets. However, you can get access to the insets and apply them manually. In androidx.compose.material 1.6.0 and later, use the windowInsets parameter to apply the insets manually for BottomAppBar, TopAppBar, BottomNavigation, and NavigationRail. Likewise, use the contentWindowInsets parameter for Scaffold.
• If your app uses views and Material Components (com.google.android.material), most views-based Material Components such as BottomNavigationView, BottomAppBar, NavigationRailView, or NavigationView, handle insets and require no additional work. However, you need to add android:fitsSystemWindows="true" if using AppBarLayout.
• For custom composables, apply the insets manually as padding. If your content is within a Scaffold, you can consume insets using the Scaffold padding values. Otherwise, apply padding using one of the WindowInsets.
• If your app is using views and BottomSheet, SideSheet or custom containers, apply padding using ViewCompat.setOnApplyWindowInsetsListener. For RecyclerView, apply padding using this listener and also add clipToPadding="false".

What to check if your app must offer custom background protection

If your app must offer custom background protection to 3-button navigation or the status bar, your app should place a composable or view behind the system bar using WindowInsets.Type#tappableElement() to get the 3-button navigation bar height or WindowInsets.Type#statusBars.

Additional edge-to-edge resources

See the Edge to Edge Views and Edge to Edge Compose guides for additional considerations on applying insets.

Deprecated APIs

The following APIs are deprecated but not disabled:

• R.attr#enforceStatusBarContrast
• R.attr#navigationBarColor (for 3 button navigation, with 80% alpha)
• Window#isStatusBarContrastEnforced
• Window#setNavigationBarColor (for 3 button navigation, with 80% alpha)
• Window#setStatusBarContrastEnforced

The following APIs are deprecated and disabled:

• R.attr#navigationBarColor (for gesture navigation)
• R.attr#navigationBarDividerColor
• R.attr#statusBarColor
• Window#setDecorFitsSystemWindows
• Window#getNavigationBarColor
• Window#getNavigationBarDividerColor
• Window#getStatusBarColor
• Window#setNavigationBarColor (for gesture navigation)
• Window#setNavigationBarDividerColor
• Window#setStatusBarColor

穩定設定

如果應用程式指定 Android 15 (API 級別 35) 以上版本，Configuration 就不會再排除系統列。如果您使用 Configuration 類別中的螢幕大小來計算版面配置，應視需求將其替換為更佳的替代方案，例如適當的 ViewGroup、WindowInsets 或 WindowMetricsCalculator。

Configuration 自 API 1 起便可供使用。通常會從 Activity.onConfigurationChanged 取得。提供視窗密度、方向和大小等資訊。Configuration 傳回的視窗大小有一項重要特徵，就是先前會排除系統列。

設定大小通常用於資源選取，例如 /res/layout-h500dp，這仍是有效的用途。不過，我們一向不建議將其用於版面配置計算。如果您這樣做，請立即停止。請視用途而定，將 Configuration 的用法替換為更合適的項目。

如果您要使用它來計算版面配置，請使用適當的 ViewGroup，例如 CoordinatorLayout 或 ConstraintLayout。如果您要使用它來判斷系統 navbar 的高度，請使用 WindowInsets。如要瞭解應用程式視窗目前的大小，請使用 computeCurrentWindowMetrics。

以下清單說明受到這項異動影響的欄位：

• Configuration.screenWidthDp 和 screenHeightDp 大小不再排除系統列。
• Configuration.smallestScreenWidthDp 會間接受到 screenWidthDp 和 screenHeightDp 變更的影響。
• Configuration.orientation 會間接受到 screenWidthDp 和 screenHeightDp 在近正方形裝置上的變更。
• Display.getSize(Point) 會間接受到 Configuration 變更的影響。這項屬性已在 API 級別 30 開始淘汰。
• Display.getMetrics() 自 API 級別 33 起就已採取此做法。

elegantTextHeight 屬性預設為 true

For apps targeting Android 15 (API level 35), the elegantTextHeight TextView attribute becomes true by default, replacing the compact font used by default with some scripts that have large vertical metrics with one that is much more readable. The compact font was introduced to prevent breaking layouts; Android 13 (API level 33) prevents many of these breakages by allowing the text layout to stretch the vertical height utilizing the fallbackLineSpacing attribute.

In Android 15, the compact font still remains in the system, so your app can set elegantTextHeight to false to get the same behavior as before, but it is unlikely to be supported in upcoming releases. So, if your app supports the following scripts: Arabic, Lao, Myanmar, Tamil, Gujarati, Kannada, Malayalam, Odia, Telugu or Thai, test your app by setting elegantTextHeight to true.

針對複雜字母形狀變更 TextView 寬度

In previous versions of Android, some cursive fonts or languages that have complex shaping might draw the letters in the previous or next character's area. In some cases, such letters were clipped at the beginning or ending position. Starting in Android 15, a TextView allocates width for drawing enough space for such letters and allows apps to request extra paddings to the left to prevent clipping.

Because this change affects how a TextView decides the width, TextView allocates more width by default if the app targets Android 15 (API level 35) or higher. You can enable or disable this behavior by calling the setUseBoundsForWidth API on TextView.

Because adding left padding might cause a misalignment for existing layouts, the padding is not added by default even for apps that target Android 15 or higher. However, you can add extra padding to preventing clipping by calling setShiftDrawingOffsetForStartOverhang.

The following examples show how these changes can improve text layout for some fonts and languages.

Standard layout for English text in a cursive font. Some of the letters are clipped. Here is the corresponding XML:

<TextView
    android:fontFamily="cursive"
    android:text="java" />

Layout for the same English text with additional width and padding. Here is the corresponding XML:

<TextView
    android:fontFamily="cursive"
    android:text="java"
    android:useBoundsForWidth="true"
    android:shiftDrawingOffsetForStartOverhang="true" />

Standard layout for Thai text. Some of the letters are clipped. Here is the corresponding XML:

<TextView
    android:text="คอมพิวเตอร์" />

Layout for the same Thai text with additional width and padding. Here is the corresponding XML:

<TextView
    android:text="คอมพิวเตอร์"
    android:useBoundsForWidth="true"
    android:shiftDrawingOffsetForStartOverhang="true" />

EditText 可感知本地化的預設行高

In previous versions of Android, the text layout stretched the height of the text to meet the line height of the font that matched the current locale. For example, if the content was in Japanese, because the line height of the Japanese font is slightly larger than the one of a Latin font, the height of the text became slightly larger. However, despite these differences in line heights, the EditText element was sized uniformly, regardless of the locale being used, as illustrated in the following image:

For apps targeting Android 15 (API level 35), a minimum line height is now reserved for EditText to match the reference font for the specified Locale, as shown in the following image:

If needed, your app can restore the previous behavior by specifying the useLocalePreferredLineHeightForMinimum attribute to false, and your app can set custom minimum vertical metrics using the setMinimumFontMetrics API in Kotlin and Java.

相機和媒體

Android 15 會針對指定 Android 15 以上版本為目標版本的應用程式，對相機和媒體行為進行下列變更。

要求音訊焦點的限制

以 Android 15 為目標的應用程式必須是頂層應用程式或執行前景服務，才能要求音訊焦點。如果應用程式嘗試要求焦點，但不符合上述其中一項要求，呼叫會傳回 AUDIOFOCUS_REQUEST_FAILED。

如要進一步瞭解音訊焦點，請參閱管理音訊焦點一文。

更新非 SDK 限制

Android 15 includes updated lists of restricted non-SDK interfaces based on collaboration with Android developers and the latest internal testing. Whenever possible, we make sure that public alternatives are available before we restrict non-SDK interfaces.

If your app does not target Android 15, some of these changes might not immediately affect you. However, while it's possible for your app to access some non-SDK interfaces depending on your app's target API level, using any non-SDK method or field always carries a high risk of breaking your app.

If you are unsure if your app uses non-SDK interfaces, you can test your app to find out. If your app relies on non-SDK interfaces, you should begin planning a migration to SDK alternatives. Nevertheless, we understand that some apps have valid use cases for using non-SDK interfaces. If you can't find an alternative to using a non-SDK interface for a feature in your app, you should request a new public API.

如要進一步瞭解此 Android 版本中的變更，請參閱「Android 15 的非 SDK 介面限制更新內容」。如要進一步瞭解非 SDK 介面的一般資訊，請參閱「非 SDK 介面的限制」。